Kizzbot wrote:Winter is just around the corner and you guys put up a fan? I am really losing interest in woot fast.
A lot of people mistakenly believe that a fan is for cooling. That's false. Fans don't cool the air. All the fan does is to push air around. You can prove this easily. Close the door in a room and turn the fan on, aimed at a thermometer. The temperature won't go down no matter ho long it blows. In fact, technically speaking, the motor actually adds heat to the air. Fans can help cool you, however, in two ways.
1) Evaporative Cooling, which applies mostly to living things (or anything with surface moisture). When liquids evaporate, the phase change carries away energy (aka heat). That cools the surface with the liquid. Sweating serves one major purpose and it's to cool the body (and NOT detoxification as some New Age healers would have you think; sweat doesn't detoxify). A fan blows air on the sweat, speeding evaporation by carrying the vapors away. This does not work, however, on very humid days where there is too much moisture in the air to accept anymore from your body. A fan would be useless.
As an aside, evaporative cooling is how those misting fans work. You spritz water on yourself and then the fan sppeds its evaporation, cooling the skin. Again, it won't work on very humid days.
As another aside, this is why you actually need to drink MORE water on hot humid days, not less. Unlike plants, which need less water because they can absorb moisture from the air, we dehydrate more easily. When it's hot, our body reacts by sweating, hoping to cool it through evaporative cooling. But since your sweat can't evaporate into the already saturated air, your body stays hot. It then reacts by sweating more, still trying to cool it via evaporation. All this futile sweating leads to water loss and dehydration.
BTW, the fact that moisture is needed is the reason the above thermometer doesn't experience any cooling from the fan. The same goes for your computer and other electronic equipment. Yet we have fans inside the computer and other electronics. For example, the bulb inside a projection TV could burn out if there was no fan. That's due to the next effect...
2) Air Circulation. When you blow air on the CPU of a computer or hot halogen bulb inside a projector, the goal is to displace the hot air with cooler air. The fan doesn't actually cool the air, it merely pushes the hot air away. This works great if the surrounding air is cooler. For example, if you have an open window, a fan can pull cooler air in. And certainly, the air 12" away from a hot CPU is cooler than the CPU. It's not as useful, however, if you're in a closed room, with no temperature differences throughout the room. You'd be circulating the same hot air around. And while you may feel cooler because of the above evaporative cooling, non-living things won't experience any cooling.
The bottom line is not to expect miracles from a fan. If it's really humid, turn on an air conditioner which will actually dehumidify the air. And to answer Kizzbot's original criticism, a fan can circulate warm air just as well as it can circulate cool air. This Vornado can then be helpful during the Winter.
